Dunite

Porphyry

Dunite and Porphyry

Dunite

Porphyry

Add ⊕

Definition

Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine

Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix

History

Origin

New Zealand

Egypt

Discoverer

Ferdinand von Hochstetter

Unknown

Etymology

From the name of Dun Mountain, New Zealand, + -ite1

From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Phaneritic

Porphyritic

Color

Dark Greenish - Grey

Black, Brown, Green, Grey, Red, Rust, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Shiny

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds

Creating Artwork, Gemstone, Jewelry

Types

Dunite

Rhomb Porphyry

Features

Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock

Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.

Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.

Composition

Mineral Content

Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene

Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica

Compound Content

Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

3.5-46-7

1 7

👆🏻

Grain Size

Coarse Grained

Fine Grained

Fracture

Irregular

Streak

White

Porosity

Less Porous

Luster

Shiny

Dull

Compressive Strength

107.55 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.1

1.7

Specific Gravity

3-3.012.5-4

0 8.4

👆🏻

Transparency

Translucent to Opaque

Density

2.84-2.85 g/cm³2.5-2.52 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.25 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey

China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam

Africa

Morocco, South Africa

Egypt, Ethiopia, Ghana, South Africa

Europe

Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland

Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

Canada, Cuba, Jamaica, USA

South America

Argentina, Brazil, Colombia, Ecuador, Venezuela

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New South Wales, New Zealand, Western Australia

All about Dunite and Porphyry Properties

Know all about Dunite and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Dunite and Porphyry belong to Igneous Rocks.Texture of Dunite is Phaneritic whereas that of Porphyry is Porphyritic. Dunite appears Rough and Shiny and Porphyry appears Dull. The luster of Dunite is shiny while that of Porphyry is dull. Dunite is available in dark greenish - grey colors whereas Porphyry is available in black, brown, green, grey, red, rust, white colors. The commercial uses of Dunite and Porphyry are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.